1. Field of the Invention
This invention relates to the supply of working fluids such as detergents, bleach, softeners, etc. to a group of washing machines installed for use in apartment buildings, dormitories, public laundries and the like.
2. Brief Description of Related Developments
Using as an example the typical dormitory environment, a group of washing machines may be installed in a location for access to the student residents of a particular building or group of apartments. These washing machines are generally coin operated and paired with dryers to provide a laundry facility. Each user brings their own detergent, bleach, and softener or whatever chemicals they choose to use in their laundry routine. Coin operated dispensers may be available to provide individual packets of detergent, etc., but there is no system, which provides for selection, payment, and dispensing of metered working fluids to a group of washing machines.
U.S. Pat. Nos. 5,195,338 and 5,758,521 describe dispensers designed for individual washing machines either domestic or commercial. These are self-contained systems involving detergent and softener reservoirs, which are operatively associated with the washer control mechanism to dispense working fluids to the washer tub. Neither of these systems are associated with payment operations.
U.S. Pat. No. 3,891,123 describes a system for dispensing multiple working fluids to a group of commercial washing machines. Chemicals which are prediluted in a main reservoir are pumped to a holding tank. Each washing machine is provided with an individual supply tank that provides a metered amount of chemical to the washing machine. There is no payment operation associated with this system.
In U.S. Pat. No. 5,014,211, a further dispensing system is shown which utilizes a system of containers and pumps, which hold and distribute working chemicals to multiple washers. The system of the '211 patent uses a water flush system to meter the chemicals. U.S. Pat. No. 5,435,157 describes another system for the same purpose. In the '156 patent water is used as a motive force to operate venturi valves that control the dispensing operation. Neither of these patents involves a payment operation.
All of the above systems are designed to minimize the need for operator interaction. This helps to avoid spills, overfilling, and mistakes in the quantity of fluid. The above systems are designed for commercial laundries in which the machines are operated by trained technicians. The problem of operator error is worse where the washing machines are part of public or semiprivate laundry operations. Yet there are no systems for automating detergent dispensing that are coupled with a payment system for use in such operations.
It is a purpose of this invention to provide a working fluid dispensing system that will automatically dispense a metered amount of detergent or other chemical to a selected washing machine in response to inputs from a user interface. It is another purpose of this invention to associate the dispensing system with a payment operation, which allows payment for both use of the washing machine and for a correct amount of working fluid, as part of the operation. It is a purpose of this invention to provide the capability of adapting the payment operation for use with a centralized payment system, such as a credit card or campus card system. It is also a purpose of this invention to optimize the use of the working fluids to minimize both operating costs and environmental impact.